UNIVERSITY  OF  CALIFORNIA  agricultural  experiment  Station 

COLLEGE   OF  AGRICULTURE  E-  J-  Wickson,  d. rector 

BERKELEY,   CALIFORNIA 


CIRCULAR  No.  54 

(August,  1910) 


Some  Creamery  Problems  and  Tests 


BY 

LEON   M.   DAVIS 

(Assistant  in  Dairy  Husbandry) 


One  of  the  ends  most  sought  by  the  creameryman  is  the  manufacture 
of  a  uniform  product.  If  he  would  successfully  market  his  butter,  this 
is  of  great  importance.  While  it  is  true  that  in  many  places  the 
markets  make  little  distinction,  still  there  is  an  ever-increasing  demand 
for  good  butter,  and  this  is  the  demand  which  the  good  creameryman 
would  supply. 

In  no  way  can  the  uniformity  of  our  creamery  products  be  more 
surely  obtained  than  through  the  keeping  of  creamery  records.  A 
study  of  the  method  blanks  which  have  been  sent  in  AAdth  the  Scoring 
Contest  butter,  and  the  scores  made  since  the  California  Scoring 
Contest  began  in  February,  1909,  reveals  the  fact  that  there  is  a  great 
lack  of  uniformity,  not  only  in  butter  made  at  different  creameries, 
but  often  in  that  made  at  the  same  creamery. 

It  also  appears,  from  these  blanks  as  well  as  from  correspondence, 
that  a  few  makers  are  not  familiar  with  some  of  the  essential  creamery 
calculations  and  tests.  While  it  is  necessary  to  keep  constantly  remind- 
ing the  average  man  of  what  he  knows,  lest  he  forget  it,  this  circular 
is  not  presented  entirely  for  that  purpose.  Most  creamerymen  are 
already  acquainted  with  everything  herein  recorded.     It  is  written 


rather  with  the  thought  of  presenting  in  a  brief  though  intelligible 
manner,  a  few  creamery  problems  and  suggestions  for  all  those  who, 
for  any  reason,  are  unfamiliar  with  them. 

Greater  uniformity  in  filling  out  method  blanks  is  also  urged.  If 
these  are  incomplete,  full  criticism  is  impossible,  and  the  chief  educa- 
tional value  of  the  Scoring  Contest  is  lost.  It  is  the  mark  of  a  good 
workman  to  be  able  to  render  a  complete  report. 

OVERRUN. 

There  is  perhaps  no  part  of  the  creamery  business  which  is  watched 
more  keenly  than  the  matter  of  overrun.  In  this  day  of  competition, 
the  cry  of  the  creamery  everywhere  is,  ''We  must  have  all  the  overrun 
possible."  Yet,  a  buttermaker  or  manager  is  occasionally  found  who 
is  not  familiar  with  overrun,  nor  with  the  factors  influencing  it.  To 
the  creameryman  who  has  not  studied  this  subject  carefully,  the  follow- 
ing should  be  helpful,  as  well  as  interesting. 

By  overrun  is  meant  the  difference  between  the  pounds  of  butter 
made  and  the  original  pounds  of  fat.  It  does  not  refer  to  the  fat  in 
the  butter,  but  to  the  fat  paid  for  in  the  milk  or  cream  from  which 
the  butter  is  made.  The  amount  of  butter  which  can  be  made  from  a 
given  amount  of  cream,  and  hence  the  overrun,  is  influenced  by  the 
following  factors : 

(1)  Test  of  the  cream.  This  determines  the  amount  of  fat 
delivered.  1000  lbs.  of  cream  testing  39%  contains  as  must  fat  as 
1500  lbs.  of  cream  testing  26%. 

(2)  Loss  of  fat  in  skim  milk.  This  usually  averages  about  .1%, 
but  is  increased  by  using  too  low  temperatures  in  separating,  by 
wrong  treatment  of  separator,  such  as  increasing  or  reducing  speed, 
or  by  overfeeding,  thereby  not  exposing  the  milk  to  centrifugal  force 
for  a  sufficient  length  of  time. 

(3)  Loss  of  fat  in  buttermilk.  This  too  varies  under  different 
conditions,  from  .04%  to  .3%.  In  churning  a  rich  cream,  there  is  less 
buttermilk ;  hence,  less  loss  than  in  thin  cream  under  the  same  con- 
dition.    High  churning  temperatures  favor  a  heavy  buttermilk  loss. 

(4)  Amount  of  water,  salt  and  curd  incorporated.  The  moisture 
content  of  butter  made  strictly  for  quality  averages  12%  to  13%,  but 
in  commercial  butter  it  varies  from  8%  to  16%.  Where  a  buttermaker 
is  not  careful,  a  variation  of  one  to  four  per  cent,  in  moisture  content 
may  be  found  in  different  churnings.  The  legal  limit  of  16%  requires 
the  buttermaker  to  keep  below  that  mark,  but  it  is  to  his  interest  to 


approach  it  as  closely  as  possible.  The  salt  content  of  our  Contest 
butter  is  found  to  vary  from  .81%  to  3.39%,  but  in  every  case  where 
it  has  gone  over  2.50%  it  has  been  criticized  for  heavy  salting.  An 
average  may  be  taken  as  2.25%,  though  salt  content  is  always  more  or 
less  variable.    Curd  incorporated  is  usually  about  1%. 

(5)  Mechanical  losses.  These  constitute  the  heaviest  fat  losses 
which  a  creamery  has  to  sustain,  and  include  losses  in  weighing,  slop- 
ping, irregularities  of  haulers,  not  rinsing  cans  or  vats,  and,  butterfat 
washed  into  drain  from  churn.  These  losses  amount  to  considerable 
at  times,  and  have  been  calculated  by  some  to  be  never  less  than  2%. 

If  the  amount  of  overrun  equals  the  difference  between  the  pounds 

of  butter  made  and  the  pounds  of  fat  paid  for,  then  the 

_             ,       _                        Butter  made — Fat  paid  for    w  .,__ 
Per  cent,  of  overrun  = X  100 


Example : 


Fat  paid  for 

Pounds  of  butter  made     =  1485 
Pounds  of  fat  paid  for      =  1240 

Pounds  of  overrun       =    245 
Per  cent,  of  overrun  =  19.75 

1485  —  1240 

X  100  =  19.75 


1240 

The  following  figures  show  the  possible  overrun  from  1000  pounds 
of  butterfat  under  different  percentages  of  loss,  and  when  butter  made 
therefrom  contains  different  percentages  of  fat. 

{Butterfat  81% 

Moisture  16 

Salt  2 

Curd  1 

100% 

Average  Average 

No  losses  buttermilk  loss  total  losses 

Possible  pounds  of  butter         1234.5  1229.6  1204.9 

Pounds  overrun  234.5  229.6  204.9 

Per  cent,  overrun  23.4  22.9  20.4 

(Butterfat  83% 

Moisture  14 

Salt  2 

Curd  1 

100% 


Possible  pounds  of  butter 
Pounds  overrun 
Per  cent,  overrun 


Composition  of  Butter 


No  losses 

Average 
buttermilk  loss 

Average 
total  losses 

1204.8 

1200 

1175.9 

204.8 

200 

175.9 

20.4 

20 

17.5 

(  Butterfat 

85% 

ter    J   Moisture 

12 

j   Salt 

2 

I  Curd 

1 
100% 

No  losses 

Average 
buttermilk  loss 

Average 
total  losses 

1176.4 

1171.7 

1148.2 

176.4 

171.7 

148.2 

17.6 

17.1 

14.8 

Possible  pounds  of  butter 
Pounds  overrun 
Per  cent,  overrun 

In  creameries  throughout  the  state  the  overrun  varies  from  10% 
to  20%.    An  excessively  high  overrun  may  be  due  to : 

1.  Short  weights. 

2.  Reading  tests  low. 

3.  Reducing  mechanical  and  other  losses  to  a  minimum. 

4.  Incorporating  too  much  water. 

Low  overrun  is  the  result  of : 

1.  Overweighing. 

2.  Reading  tests  too  high. 

3.  Excessive  losses. 

4.  Making  butter  of  a  high  fat  content. 

STARTER  MAKING. 

From  the  standpoint  of  the  judge,  there  is  nothing  about  butter 
which  is  criticized  as  is  flavor.  Next  to  having  good  raw  material  to 
work  with,  there  is  perhaps  no  other  factor  which  is  of  more  im- 
portance in  producing  good  flavor  than  is  the  use  of  good  starter.  But, 
just  as  it  is  impossible  to  make  good  butter  from  poor  cream,  so,  it  is 
impossible  to  make  good  starter  from  poor  milk.  It  is  apparent,  then, 
that  the  securing  of  good  milk  for  starter  making  must  first  be  given 
attention,  and  though  such  often  becomes  a  problem,  yet,  in  this  day 
of  gathered  cream  butter-making,  it  is  usually  a  problem  worth  solving. 

Starter  propagation  is  nothing  more  nor  less  than  the  growing  of 
lactic  acid  bacteria,  and  all  precautions  observed  in  so  doing  are  merely 
to  furnish  a  favorable  environment  for  such  growth.  The  addition  of 
a  commercial  culture  to  sterile  milk  introduces  pure  lactic  acid  bacteria 


in  such  numbers  that,  under  ordinary  methods  of  sterilization,  their 
growth  predominates  any  other  type  which  may  be  present. 

In  order  to  properly  and  successfully  make  starter,  two  points 
must  be  constantly  kept  in  mind,  namely, — sterilization,  and  freedom 
from  contamination.  For  the  ordinary  person,  it  is  hard  to  realize  that 
the  use  of  a  dirty  dipper  may  contaminate  a  whole  can  of  starter,  yet 
this  is  not  only  scientifically  but  also  practically  true. 

For  the  propagation  of  mother-starters,  glass  vessels  should  be  used, 
as  they  are  easily  cleaned,  are  transparent,  and  are  not  subject  to  rust 
as  are  metal  vessels.  An  ordinary  quart  milk  bottle  is  satisfactory,  and 
may  be  made  sterile  by  inverting  over  a  steam  jet  for  about  fifteen 
minutes,  or  by  placing  in  the  sterilizer  cabinet  mentioned  later.  In 
either  case,  steam  must  be  turned  on  carefully,  for  these  bottles  are 
not  of  uniform  thickness,  and  uneven  expansion,  due  to  heat,  may 
cause  them  to  break. 

Preparation  of  milk  for  mother  starter.  After  the  sterilized  bottle 
has  cooled,  fill  it  about  three-fourths  full  of  good  skim  milk,  and  cap. 
This  is  ordinary  milk,  and  at  the  best,  will  contain  organisms  which 
will  be  of  no  aid  in  starter  making.  Hence,  it  too  must  be  sterilized. 
There  are  various  ways  of  doing  this.  One  of  the  most  satisfactory  is 
the  use  of  a  sterilizer  cabinet,  which  is  merely  a  covered  can  with 
perforated  bottom,  so  that  it  can  be  placed  over  a  steam  jet,  allowing 
the  steam  to  circulate  inside.  A  thermometer  may  be  placed  through 
the  top  of  this  can.  If  such  a  sterilizer  is  not  obtainable,  the  milk  may 
be  heated  by  placing  bottles  in  a  bucket  of  water,  into  which  a  steam 
hose  can  be  introduced.  If  the  latter  method  is  followed,  it  will  be 
necessary  to  fasten  the  bottles  in  some  way,  as  there  will  be  more  or 
less  motion  in  the  w7ater  when  the  steam  is  turned  on.  Heat  this  water 
to  190°  F.-2000  F.  for  thirty  minutes,  then  gradually  cool  to  70°,  by 
slowly  running  cold  water  into  the  bucket.  Let  the  bottles  remain  in 
this  water  until  the  milk  has  had  time  to  cool  thoroughly.  Never  put 
a  thermometer  into  sterile  milk,  as  it  may  carry  contamination.  If 
poor  milk  has  been  used,  it  will  be  necessary  to  repeat  the  heating  on 
the  second  daj^,  as  the  resistant  forms  of  bacteria,  or  spores,  are  not 
killed  the  first  day,  and  will  germinate,  spoiling  the  milk.  But  if  good 
milk  is  used,  cooled  immediately,  and  inoculated,  there  is  found  to  be 
little  danger  from  these  spores,  as  lactic  acid  development  takes  place 
so  rapidly  as  to  be  unfavorable  for  their  development. 

Making  the  inoculation.  Pure  lactic  acid  cultures,  as  sent  out  by 
commercial  laboratories,  exist  in  two  forms — dry  and  liquid — and  it  is 
a  matter  of  personal  choice  on  the  part  of  the  buttermaker  which  of 


these  forms  he  will  use.  The  first  inoculation  is  made  by  adding  the 
entire  contents  of  a  bottle  or  package  of  culture  to  a  bottle  of  sterile 
milk.  Danger  of  contamination  at  this  time,  may  be  prevented  by 
naming  the  necks  of  both  bottles  with  an  alcohol  flame,  previous  to  the 
transfer.  The  bacteria  may  be  distributed  throughout  the  milk  by 
shaking,  and  this  is  especially  important  if  the  culture  was  in  dry 
form.  Inoculated  milk  wall  usually  curdle  in  twenty-four  hours,  or 
less,  if  kept  at  a  temperature  of  70° -85°  F.  The  bottle  of  starter 
resulting  from  the  first  inoculation  will  have  a  powdery,  sweet  taste, 
and  should  not  be  used  in  cream  ripening,  but  this  will  usually  dis- 
appear after  the  second  or  third  inoculation,  and  instead  there  will 
be  a  sharp  pleasant  flavor,  and  a  curd  of  good  granular  texture. 

To  successfully  propagate  mother-starter,  it  is  necessary  to  go 
through  the  before-mentioned  process  of  sterilization  daily,  inoculating 
a  fresh  bottle  of  sterile  milk  from  the  bottle  of  starter  made  the  pre- 
vious day.  It  is  well  to  examine  this  starter,  and  such  can  be  done 
just  before  making  the  inoculation.  Pour  a  small  amount  into  a  cup, 
taste,  smell,  and  test  for  acidity.  Do  not  pour  the  portion  examined 
back  into  bottle,  but  throw  it  away,  as  it  has  likely  become  con- 
taminated. If  the  examination  shows  the  starter  to  be  all  right,  pour 
a  small  amount  into  the  bottle  of  sterile  milk,  and  shake  the  latter 
well  to  distribute  the  bacteria  throughout. 

In  preparing  starter  for  cream  ripening,  the  work  is  done  on  a 
much  larger  scale.  There  are  several  styles  of  starter  cans,  each 
differently  designed,  but  all  answering  the  same  purpose.  Nothing 
more  than  a  general  outline  can  be  given  for  using  any  of  them,  as 
many  conditions  must  be  considered.  The  same  care  must  be  exerted 
as  in  handling  mother  starters,  but,  even  under  the  most  careful  treat- 
ment, it  is  impossible  to  totally  prevent  contamination.  Thus  is  seen 
the  necessity  of  the  mother  starter. 

One  day 's  starter  making  : 

1.  Pasteurize  freshly  separated  skim  milk  in  starter  can,  at  a 
temperature  of  185°  F.  for  twenty  to  thirty  minutes,  then  cool 
to  70° -85°  F.,  stirring  continually. 

2.  Sterilize  and  cool  bottle  of  skim  milk. 

3.  Examine  mother  starter  made  previous  day,  and  if  all 
right  inoculate  from  it  the  bottle  of  sterile  milk  and  starter  can 
of  pasteurized  milk. 

4.  Keep  these  at  a  temperature  of  70°-85°  F.,  until  ripened, 
then  cool  to  50° -60°  F.,  if  they  are  to  be  held  any  length  of  time 
before  using.  Do  not  stir  or  shake  after  first  signs  of  curdling 
appear. 


The  matter  of  temperature  control  will  be  seen  to  be  of  importance. 
The  construction  of  a  starter  can  is  such  that  trouble  from  that  source 
is  reduced  to  a  minimum,  but,  the  bottles  containing  the  mother  starter 
require  attention,  unless  special  apparatus  is  at  hand.  In  many  parts 
of  California,  ordinary  room  temperature  is  favorable  much  of  the 
year,  but  in  cool  weather,  some  part  of  the  boiler  room  is  more  suitable. 
When  the  bottle  of  starter  is  ripe,  it  can  be  placed  in  a  cold  storage 
room,  for,  at  a  temperature  of  50°  F.,  or  below,  bacterial  growth  is 
retarded,  and  the  organisms  remain  in  dormant  state. 

It  often  happens  that  a  starter  develops  a  bad  flavor,  or  becomes 
contaminated  with  gas  producing  bacteria.  In  such  a  case,  a  butter- 
maker  realizes  the  value  of  carrying  two  mother  starters.  Many  do 
carry  two.  starters,  as  so  doing  requires  but  little  more  time.  The 
period  a  starter  will  last  can  not  be  foretold,  so  the  only  rule  to  follow 
is, — use  while  good,  and  when  it  "goes  off,"  throw  it  away. 

Good  starter  has  a  clean  mild  acid  flavor,  a  delicate  aroma,  and  a 
smooth  granular  body.  The  acidity  should  be  about  .7%,  for  at  that 
point  the  greatest  number  of  bacteria  are  present.  If  a  higher  acidity 
is  developed,  there  is  a  tendency  for  the  starter  to  become  hard  and 
lumpy. 

COLOEING. 

No  creameryman  needs  an  explanation  of  the  terms  "mottled"  or 
"wavy  or  streaky  color."  They  refer  to  a  difference  or  unevenness  of 
color,  and  appear  in  butter  as  irregular,  lighter  and  darker  portions, 
and  often  as  spots. 

The  general  opinion  regarding  these  defects  seems  to  be  that  they 
are  the  result  of  uneven  salting.  This  is  in  part  the  cause,  but 
another  factor  enters,  and  that  is  the  presence  of  buttermilk  or  casein 
compounds.  Salt  as  put  into  butter  should  be  dissolved  by  the  water 
present,  and  a  brine  solution  result.  If  butter  contains  casein  com- 
pounds, left  in  by  failure  to  remove  all  the  buttermilk,  they  are  acted 
upon  and  hardened  by  this  brine  solution.  Consequently,  when  the 
butter  is  worked,  streaks  and  spots  result.  Where  these  streaks  and 
spots  occur,  the  lighter  portions  are  due  to  the  presence  of  casein 
compounds.  The  yellow  and  clear  portions  are  free  from  these,  and 
the  fat  is  surrounded  by  clear  brine.  Well  washed  butter  very  seldom 
shows  mottles,  unless  the  salting  is  done  unevenly. 

Mottled  or  streaky  butter,  then,  may  be  prevented  by  churning 
at  a  low  temperature  to  keep  the  butter  in  fine  granules,  washing 
thoroughly,  and  working  sufficiently  to  insure  equal  distribution  of 


salt.  Even  under  these  conditions,  a  certain  amount  of  buttermilk 
will  be  retained  within  the  granules,  but  not  sufficient  to  cause  these 
defects. 

Mottles  or  streaks  do  not  necessarily  detract  from  the  palatability 
and  wholesomeness  of  butter,  but  the  fact  that  present  day  markets 
are  governed,  to  a  great  extent,  by  appearances,  makes  it  the  more 
important  that  every  buttermaker  guard  against  them. 

ACIDITY. 

The  best  flavor  in  butter  is  produced  when  cream  has  reached  the 
proper  acidity.  Although  many  buttermakers  receive  poor  cream, 
it  is  evident  also  that  many  ripen  it  improperly  before  churning; 
hence  the  importance  of  the  acid  test. 

A  few  experienced  makers  are  able,  by  taste  and  smell,  to  ascertain 
approximately  when  the  proper  degree  of  acidity  has  been  reached,  but 
a  special  test  which  will  measure  the  exact  amount  of  acid  present,  is 
more  to  be  relied  upon,  as  the  flavor  of  ripened  cream  varies  some- 
what with  different  degrees  of  richness.  Before  a  man  can  intelligently 
test  milk  or  cream,  he  must  know  why  he  does  certain  things.  It  may 
be  helpful,  therefore,  to  those  creamerymen  who  are  not  familiar 
with  the  common  and  practical  acid  tests  in  use,  to  outline  briefly  the 
principle  and  the  manner  of  making  these  tests. 

The  acid  tests  most  commonly  used  in  creameries  are :  Marschall  's, 
Manns',  and  Farrington's  Alkaline  Tablet  test.  All  of  these  are  based 
on  the  principle  that  a  definite  amount  of  alkali  solution  of  known 
strength  will  neutralize  a  definite  amount  of  lactic  acid.  By  chemistry 
we  are  able  to  determine  that  one  cubic  centimeter  of  one-tenth  normal 
sodium-hydroxide  solution,  which  is  the  alkaline  neutralizer  used 
generally,  will  combine  with  exactly  .009  gram  of  lactic  acid.  In  order 
that  we  may  determine  with  the  eye  just  when  all  of  the  lactic  acid 
in  the  milk  or  cream  being  tested  has  been  neutralized  by  this  alkaline 
solution,  an  indicator  is  used  which  shows  by  a  change  of  color  when 
this  point  is  reached.  In  making  a  test,  therefore,  as  long  as  any  free 
lactic  acid  remains  in  the  milk  or  cream  the  color  remains  white,  but 
when  all  the  lactic  acid  has  been  neutralized  by  the  alkaline  solution, 
it  changes  to  pink,  and  if  an  excess  of  alkaline  solution  is  put  in,  it 
becomes  red. 

In  order  to  get  an  accurate  test,  it  is  necessary  that  the  proper 
pinkish  shade  to  attain  be  well  in  mind,  and  this  may  be  determined  in 
the  following  way: 

Place  two  samples  of  milk  or  cream  in  white  dishes,  side  by  side, 


and  dilute  each  with  its  own  volume  of  distilled  water.  Dishes  with 
wide  tops  will  expose  more  surface  to  view,  and  the  addition  of  dis- 
tilled water  will  thin  the  sample,  and  aid  in  noting  any  color  changes. 
Add  a  few  drops  of  indicator  to  one,  then  stir  with  a  rod  and  run 
neutralizer  in  slowly,  until  the  first  suggestion  of  pink  color. appears, 
which  will  indicate  the  turning  point.  By  comparing  a  sample  being 
tested,  with  the  original,  it  is  much  easier  to  notice  the  first  change 
of  color.  Using  the  neutralized  sample  as  a  color  standard,  color  a 
small  amount  of  skim  milk  to  the  same  shade  by  the  use  of  a  few  drops 
of  diluted  carmine  ink.  Such  a  sample  may  be  kept  from  curdling 
by  the  use  of  uncolored  preservative,  which  must,  however,  be  added 
before  the  ink.  This  skim  milk,  of  standard  color  for  acid  titration, 
may  then  be  bottled  and  sealed,  and  kept  with  the  acid  test  for  com- 
parison as  each  test  is  made. 

The  alkaline  solution  in  general  use  for  acid  testing,  is  a  one-tenth 
normal  sodium-hydroxide  solution.  By  a  one-tenth  normal  solution  is 
meant  one  containing  just  one-tenth  as  much  sodium-hydroxide  as  a 
standard  solution.  Again  by  chemistry  Ave  learn  that  a  standard 
sodium-hydroxide  solution  contains  exactly  40  grams  of  sodium- 
hydroxide  in  1000  c.c.  of  distilled  water.  Therefore,  a  one-tenth 
normal  solution  contains  4  grams  of  sodium-hydroxide  in  1000  c.c.  of 
distilled  water.  It  is  not  possible  for  the  average  person  to  make  these 
solutions,  as  one  properly  standardized  requires  the  work  of  a  chemist. 
They  may  be  obtained  at  all  dairy  supply  houses  and  at  some  drug 
stores. 

MAESCHALL'S  ACID  TEST. 


Apparatus 


Combined  bottle  and  burette,  the  latter  graduated  to  c.c. 
9  c.c.  pipette 
Bottle  of  indicator 
White  tea  cup 


Making  tlic  test. — Measure  into  the  cup,  9  c.c.  of  sample  to  be 
tested.  The  pipette  should  be  rinsed  with  distilled  water,  and  the 
rinsings  put  in  cup  also,  for  this  does  not  affect  the  amount  of  acid 
present,  inasmuch  as  the  distilled  water  is  pure.  Caution  is  given 
against  using  ordinary  water,  as  it  may  contain  a  large  amount  of 
alkali.  Condensed  steam  from  a  steam  pipe,  or  rain  water  can  be  used 
in  place  of  distilled  water,  as  these  are  free  from  impurities.  To  the 
sample,  now  add  a  few  drops  of  indicator.  Fill  the  graduated  burette 
to  zero  with  alkaline  solution,  and  run  the  latter  into  cup  slowly  until 
a  pink  color  remains  after  shaking.  The  sample  may  be  kept  well 
mixed  by  giving  it  a  rotary  motion  while  the  test  is  being  made.    When 


10 

the  pink  color,  as  determined  by  the  standard,  is  attained,  read  from 
the  burette  the  amount  of  neutralizer  used.  Each  c.c.  of  neutralizer 
is  equivalent  to  one-tenth  per  cent,  acid,  for  1  c.c.  of  one-tenth  normal 
sodium-hydroxide  neutralizes  .009  grams  lactic  acid,  and  9  c.c.  of  milk 
or  cream  are  used. 

1  c.c.  neutralizer  X  .009  grams  lactic  acid  

X  J  00  —  .1  /o 

9  c.c.  milk  or  cream 

Thus,  if  6  c.c.  of  neutralizer  are  used,  the  per  cent  of  acid  equals 

.6%,  or  if  4.2  c.c,  the  per  cent,  of  acid  equals  .42%. 

MANNS'  ACID  TEST. 

C  Burette  graduated  to  1/10  c.c. 
Apparatus    J   Pip^te  measuring  any  known  amount 
J   Bottle  of  indicator 
v  White  tea  cup 

Making  the  test.  Measure  into  cup  with  pipette,  any  known  amount 
of  sample,  rinse  and  add  indicator  as  in  the  previous  test.  Fill  the 
graduated  burette  to  zero  with  alkaline  solution,  and  run  latter  into 
cup  until  proper  shade  is  attained,  using  the  precautions  before  men- 
tioned. From  the  c.c  of  neutralizer,  and  the  c.c.  of  sample  used,  the 
per  cent,  of  acid  is  calculated  by  the  following  formula : 

_  .       „       .,        c.c.  neutralizer  X  .009         ,A„ 

Per  cent,  of  acid  =  X  100 

c.c.  sample  used 

Thus,  if  17.6  c.c.  of  cream  require  7  c.c.  of  neutralizer, 

7  X  -009   X  100  =  .35%  acid 
17.6 

or,  if  50  c.c.  cream  requires  20.4  c.c.  neutralizer, 

20-4X-009X100  =  .36%acid 
50 

or,  if  9  c.c.  cream  require  4  c.c.  neutralizer, 

4  X  .009 


9 


X  100  =  .4%  acid 


FARRINGTON'S  ALKALINE  TABLET  TEST. 

f  100  c.c.  graduated  cylinder 
Apparatus     -j  17.6  c.c.  pipette 
(,  White  tea  cup 

Solution.    For  this  test  the  solution  is  made  up  from  alkali  tablets, 
which  already  contain  the  indicator.     Each  tablet  contains  a  definite 


11 

amount  of  alkali,  so  that  a  solution  for  testing  17.6  c.c.  of  cream  is 
made  by  placing  five  of  them  in  the  graduated  cylinder,  and  filling 
the  latter  with  distilled  water  to  the  97  c.c.  mark.  The  tablets  must  be 
thoroughly  dissolved  before  the  solution  is  ready  for  use,  and  this  may 
be  accomplished  more  quickly  if  a  cylinder  is  such  that  it  may  be 
corked  and  laid  horizontally. 

Making  the  test.  Measure  into  the  cup,  17.6  c.c.  of  sample,  and 
rinse  as  in  previous  tests.  Add  the  tablet  solution  carefully  until,  after 
shaking  or  stirring,  a  pink  shade  remains,  indicating  that  all  the  acid 
in  the  sample  has  been  neutralized  by  the  alkaline  solution.  Each  c.c. 
of  tablet  solution  required  for  neutralization  is  equivalent  to  .01% 
acid.  Thus,  if  21  c.c.  are  required,  the  per  cent,  of  acid  is  .21%,  or  if 
47  c.c.  are  required,  the  per  cent,  of  acid  is  .47%. 

A  few  buttermakers  report  the  acidity  in  terms  other  than  per 
cents.,  and  it  is  impossible  to  tell  what  acidity  they  are  using  for 
churning.  From  the  simple  method  of  calculation  given  under  Manns ' 
test,  it  is  very  easy  to  determine  the  per  cent.,  and  such  would  be  of 
value  in  making  criticisms.  Acidity  reported  in  terms  of  degrees,  or, 
cubic  centimeters,  has  no  meaning  to  one  who  does  not  know  exactly 
how  the  test  was  made,  whereas,  a  definite  per  cent,  of  acid  has  a 
universal  meaning.    Always  report  acidity  in  per  cent. 

MOISTUEE  TESTING. 

Anyone  who  is  familiar  with  testing  of  butter  for  moisture  is  well 
aware  of  the  fact  that  an  accurate  test  is  not  possible  unless  the  sample 
taken  for  testing  is  a  representative  one.  In  view  of  the  heavy  penalties 
imposed  because  of  excessive  moisture,  no  buttermaker  can  afford  to  do 
the  work  ignorantly  or  carelessly.  The  matter  of  proper  ways  of  taking 
samples  and  of  testing  is  as  yet  more  or  less  unsettled,  but  the  follow- 
ing suggestions  and  precautions  are  generally  recognized  as  being 
worthy  of  attention. 

(1)  In  taking  a  sample  from  the  churn,  remove  a  portion  of  the 
surface  of  the  butter  at  various  places  of  the  churn,  and  by  means  of 
a  spatula  take  out  small  pieces.  Butter  in  the  churn  contains  many 
water  pockets  and  these  must  be  avoided,  as  they  are  worked  out  in 
packing.  In  sampling  from  a  cube,  take  with  a  trier  from  several 
different  places;  one  in  the  middle,  and  the  others  between  this  and 
the*  edges.  The  trier  should  extend  the  full  depth  of  the  cube.  Unless 
the  trier  is  used  carefully,  the  free  water  appearing  on  the  surface  of 
the  butter  will  be  lost,  but  this  should  be  placed  with  the  butter  in 


12 

the  sample  jar.  A  wire  or  thread  is  recommended  for  taking  samples 
from  a  print,  as  butter  can  be  cut  easily  in  this  way.  Several  small 
slices  from  different  parts  of  the  print  are  sufficient.  An  ordinary 
fruit  jar  is  a  very  satisfactory  container  for  moisture  samples  and, 
after  they  are  placed  in  it,  the  cap  should  be  screwed  down  air-tight. 

(2)  Samples  taken  as  above  are  approximate  representatives  only, 
so  in  order  that  the  portions  taken  may  become  a  homogeneous  mixture, 
it  is  necessary  that  they  be  melted  at  as  low  a  temperature  as  possible 
(not  above  120°  F.)  in  order  that  none  of  the  volatile  substance  pass 
off  as  vapor,  and  then  cooled  until  solid,  shaking  often  to  insure  the 
even  distribution  of  constituents. 

(3)  Special  scales  for  moisture  testing  are  on  the  market,  and  are 
sensitive  enough  to  give  very  satisfactory  results.  They  must  be  kept 
free  from  dampness,  and  should  be  balanced  and  kept  free  from 
draughts  while  in  use.  The  aluminum  cups  used  in  most  moisture 
tests  are  capable  of  taking  moisture  from  the  air,  if  allowed  to  get 
thoroughly  cool  before  weighing.  In  order  that  these  cups,  and  also 
the  container,  may  be  dry  and  ready  for  use  at  any  time,  they  may 
be  cleaned  and  inverted  over  a  steam  pipe  after  each  test. 

(4)  If  a  quick  or  direct  flame  test  is  employed,  there  is  danger  of 
burning  the  sample,  unless  constant  attention  is  given  to  it.  Regardless 
of  the  special  test  used,  all  samples  should  be  evaporated  to  constant 
weight ;  that  is,  they  should  be  reheated  and  re  weighed  until  the  per 
cent,  of  moisture,  as  determined,  remains  constant. 

(5)  Every  buttermaker  should  occasionally  make  duplicate  tests 
to  determine  the  accuracy  of  his  work.  If  the  moisture  test  of  butter 
sent  to  the  Scoring  Contest,  as  determined  at  the  creamery,  is  to  be 
compared  with  the  test  made  by  the  Division  of  Dairy  Industry,  the 
sample  for  testing  at  the  creamery  should  not  be  taken  from  the  churn, 
but  from  a  cube  or  print.  A  sample  from  the  churn  will  usually  show 
one  per  cent,  more  moisture  than  a  sample  of  the  same  butter  from  a 
cube  or  print,  and,  after  the  cube  has  been  shipped  and  held  in  storage 
from  one  to  four  days,  as  is  often  the  case  with  Contest  butter,  the 
difference  will  be  still  greater. 

The  special  points  to  be  emphasized  in  moisture  testing  are : 

1.  An  accurate,  representative  sample. 

2.  A  homogeneous  mixture  of  constituents. 

3.  Good  scales. 

4.  Accurate  weighing. 

5.  Reheating  and  reweighing  to  constant  weight. 


13 


SALTING. 


As  stated  before,  the  salt  content  of  entries  sent  in  has  varied 
from  .81%  to  3.39%,  bnt  that,  invariably,  criticism  for  high  salting 
was  made  when  it  went  over  2.5%.  The  most  general  criticisms 
regarding  salt  are,  "too  much  salt,"  " grittiness, "  or  "uneven  salt- 
ing." The  first  of  these  is  due  to  an  excessive  amount  of  salt  being 
put  into  the  butter,  either  from  a  desire  of  the  buttermaker  to  cover 
up  undesirable  flavors,  or  to  a  lack  of  system  in  measuring  salt.  There 
is  no  excuse  for  this,  as  salt  is  one  of  the  most  easily  governed  con- 
stituents of  butter.  Again  is  emphasized  the  need  of  uniformity, 
especially  as  salt  in  butter  is  becoming  of  more  general  interest. 

The  object  of  salting  is  not  to  increase  overrun.  Quality  is  not  to 
be  sacrificed  for  quantity,  for  the  consumer's  rights  must  be  regarded. 
Grittiness  and  uneven  salting  are  related  to  each  other,  and  quite  often 
the  former  is  due  to  the  latter.  Uneven  salting  occurs  when  butter 
is  not  worked  sufficiently  to  distribute  the  salt  evenly,  and  also,  to  a 
limited  extent,  if  the  maker  is  not  careful  when  putting  salt  in  the 
churn  to  get  it  well  scattered.  Grittiness  may  be  due  to  uneven  salting, 
whereby  there  exists  in  one  portion  of  the  butter  an  excess  of  salt  and 
more  than  can  be  dissolved  by  the  water  present.  It  is  also  the  result 
of  using  too  much  salt,  or  of  using  impure  salt,  which  contains  insoluble 
substances. 

Defects  in  salt  can  no  doubt  be  overcome  by  wet  salting,  which  was 
recommended  in  a  former  report,  and  which  was  outlined  as  follows : 

For  each  10  pounds  of  butter,  mix  1  pound  of  salt  and  2  pounds  of 
water.  Bring  salt  and  water  together  thirty  minutes  before  using. 
After  butter  is  drained,  add  the  brine,  revolve  ten  times  on  slow  gear, 
and  allow  to  stand  ten  minutes  before  working.  The  amount  and  time, 
however,  can  be  varied  somewhat  to  suit  individual  conditions. 

Any  serious  defects  in  salt  may  be  determined  by  taste,  but,  in 
determining  the  uniformity  of  salt  in  butter  from  day  to  day,  a  salt 
test  is  necessary  as  the  taste  is  to  be  relied  upon  only  in  determining 
extremes.  Practical  salt  tests  may  be  obtained  at  dairy  supply  houses, 
and  the  use  of  one  enables  a  maker  to  determine  accurately  the  per 
cent,  of  salt  retained  in  his  butter.  The  principle  of  these  tests  is  the 
same,  and  may  be  given  as  follows :  A  silver  nitrate  solution  of  known 
strength  neutralizes  a  definite  amount  of  sodium  chlorid,  or  common 
salt.  By  titration,  in  the  presence  of  an  indicator  (potassium 
chromate  solution)    it  is  possible  to  determine,  by  the  color  of  the 


14 

precipitate,  when  all  the  salt  has  been  neutralized,  and  from  the 
amount  of  neutralizer  or  silver  nitrate  solution  used,  the  amount,  and 
hence  the  percentage  of  salt  in  the  butter  analyzed  can  be  calculated. 
Full  directions  for  making  these  tests  are  sent  with  each  set  of 
apparatus. 


